Rubin-LSST

Abstract:

A search for contact interactions has been performed using dimuon events recorded with the ATLAS detector in proton-proton collisions at √s=7TeV. The data sample corresponds to an integrated luminosity of 42pb-1. No significant deviation from the standard model is observed in the dimuon mass spectrum, allowing the following 95% C.L. limits to be set on the energy scale of contact interactions: Λ>4.9TeV (4.5 TeV) for constructive (destructive) interference in the left-left isoscalar compositeness model. These limits are the most stringent to date for μμqq contact interactions. 2011 American Physical Society.

Abstract:

Results are presented of searches for the production of supersymmetric particles decaying into final states with missing transverse momentum and exactly two isolated leptons in √s = 7 TeV proton-proton collisions at the Large Hadron Collider. Search strategies requiring lepton pairs with identical-sign or opposite-sign electric charges are described. In a data sample corresponding to an integrated luminosity of 35 pb-1 collected with the ATLAS detector, no significant excesses are observed. Based on specific benchmark models, limits are placed on the squark mass between 450 and 690 GeV for squarks approximately degenerate in mass with gluinos, depending on the supersymmetric mass hierarchy considered. © 2011 CERN for the benefit of the ATLAS collaboration.

Abstract:

In this Letter we discuss the recently discovered radio transient in the nuclear region of M82. It has been suggested that this source is an X-ray binary, which, given the radio flux density, would require an X-ray luminosity,LX~ 6 × 1042ergs-1 if it were a stellar mass black hole that followed established empirical relations for X-ray binaries. The source is not detected in the analysis of the X-ray archival data. Using a 99 per cent confidence level upper limit we find thatLX≤ 1.8 × 1037and 1.5 × 1037ergs-1, using power law and disc blackbody models, respectively. The source is thus unlikely to be a traditional microquasar, but could be a system similar to SS433, a Galactic microquasar with a high ratio of radio to X-ray luminosity. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.